MSA-11

Written by: Midas Date: February 2010

Thanks to: Matt and Tomek For more info: www.ecuconnections.com

Contact: Carmapping@gmail.com Revision: 1.0

Index: Introduction 3 Map explanations 4 Fuel related maps 5 1. Drivers wish 5 2. Torque limiter 7 3. Smoke limiter 8 4. Quantity adjuster map 10 5. Tuning the fuel maps 12 Conclusion 16

Introduction: The MSA-11 ECU is used in older cars like a BMW e36 325TDS which also will be the example. It has two 27C256 EPROM's inside (UV-erasable). The EPROM's are mounted in sockets, so no soldering is needed. On the EPROM with the lowest software number are the limitation maps, drivers wish and the quantity adjuster map. The EPROM with the higher software number contains the Beginning of injection maps (3 the same maps in this case). Sometimes other EPROM's are used like the 87C257 (UV-erasable). The MSA-11 is used in the following cars: ALFA 155 2.5 TD ALFA 164 2.5 TD BMW 318 TDS BMW 325 TDS BMW 525 TDS BMW 725 TDS FIAT MAREA 2.4 TD LANCIA KAPPA 2.4 TD FREELANDER 2.0 D OPEL TD's RANGE ROVER II 2.5 DTI ROVER 825 2.5 TD There may be more cars using MSA-11 which are not in the list.

Map explanations: The MSA-11 ECU has no boost control, only fuel-management. The boost is regulated mechanically. Fuel related maps: -Drivers Wish -Torque limiter -Smoke limiter -Quantity adjuster

Fuel related maps 1. Drivers wish Map: General: This map shows the required injected quantity diesel into the engine depending on the RPM and the Throttle position. The output of this map is injected quantity (IQ) in mg diesel/stroke.

Picture 1.1: 3D view of the drivers wish map.

Factors & offsets: All factors, offsets, axis descriptors and names are given by the pictures below.

Picture 1.2: The factor and offset from the map drivers wish

Picture 1.3: The properties of the X axis of the map drivers wish

Picture 1.4: The properties of the Y axis of the map drivers wish

2. Torque limiter: General: This map limits the injected quantity of diesel based on RPM. The output of this map is also mg diesel / stroke. So if the drivers wish is 50mg, and the torque limiter is 45 at that location, it won't inject 50mg but limit injection at 45mg/stroke.

Picture 2.1: 2D view of the Torque limiter

Factors & offsets: All factors, offsets, axis descriptors and names are given by the pictures below.

Picture 2.2: The factor and offset from the Torque limiter Picture 2.3: The properties of the X axis of the Torque limiter

3. Smoke limiter: General: This map limits the injected quantity of diesel based on RPM and inlet air. So if the drivers wish is 40mg, and there is only enough air to burn 35mg diesel, it won't inject 40mg but limit injection at 35mg/stroke.

Picture 3.1: 3D view of the Smoke limiter

Factors & offsets: All factors, offsets, axis descriptors and names are given by the pictures below.

Picture 3.2: The factor and offset from the Smoke limiter

Picture 3.3: The properties of the X axis of the Smoke limiter

Picture 3.4: The properties of the Y axis of the Smoke limiter

4. Quantity adjuster: General: This map shows how much volt the diesel pump need to inject a certain amount of diesel. So this is a "calibration" map.

Picture 4.1: 3D view of the Quantity adjuster map

Factors & offsets: All factors, offsets, axis descriptors and names are given by the pictures below.

Picture 4.2: The factor and offset from the Quantity adjuster map

Picture 4.3: The properties of the X axis of the Quantity adjuster map

Picture 4.4: The properties of the Y axis of the Quantity adjuster map

5. Tuning the fuel maps: If we want to tune a stock engine we need to change the drivers wish, torque limiter, smoke limiter and in this case (BMW 325tds) also the quantity adjuster. Drivers wish: The drivers wish is not very high in the original so it needs to be set higher. At full throttle it may be set 25% higher as original. Also at high revs from 50-100% throttle it may be a bit higher. To give an example, look at the picture below. It is an original text view of the torque limiter.

Picture 5.1: The original Drivers wish The modified torque limiter can look something like the picture below.

Picture 5.2: The modified Drivers wish If we look at this you can see that we have a problem. The requested injected quantity at full throttle should be 50mg x 1,25% = 63 mg/stroke. We can only add this value up to 51 because that is the upper limit of the map (255 x 0.2 = 51). This problem also occurs by the torque limiter and by the smoke limiter. Of course there is a solution: changing the quantity adjuster map. This will be discussed later.

Torque limiter: The torque limiter can be increased from 1250rpm to 4800rpm by ± 25%. The highest value should be around 4000rpm, due to the big turbo mounted on this car. To give an example, look at the picture below. It is an original text view of the torque limiter.

Picture 5.3: The original torque limiter The modified torque limiter can look something like the picture below.

Picture 5.4: The modified torque limiter We also see that the same problem occurs as the one with the drivers wish. it cannot be set higher as 51mg/stroke. Smoke limiter: As you can see the values (mg/stroke) are increased. At this point the smoke limiter will still limit the IQ. So we need to change the smoke limiter as well. We only want to change the smoke limiter at high IQ's. Original the text view of the smoke map looked like the picture 5.5.

Picture 5.5: The original smoke limiter At full throttle only the higher airflow parts will be used.

To change the smoke limiter not too much (we don't want to smoke a lot). The air fuel ratio at which not too much smoke appears is 1:17. So if we pick the value 870 (highest value on smoke map scale) and divide that by 17 we get: 870/17 = 51mg. So the max value in the most right column may be 51 mg/stroke. Then the smoke limiter looks like the picture below.

Picture 5.6: The modified smoke limiter And, again, we run into the limits of the map(51mg/stroke). Quantity adjuster map: The problem is that the system will max allow 51mg/stroke to inject. To solve this problem we let the ECU believe that it is injecting 51mg/stroke, but actually is injecting more. How do we do that? By changing the quantity adjuster map.

Picture 5.7: The original quantity adjuster map

We demand the ECU to apply more voltage for an amount of injected quantity diesel.

Picture 5.8: The modified quantity adjuster map Don't "over tune" this map. Adding 10% at higher IQ's above 1500 rpm can be a guideline.

Conclusion: All information and values given in this document may be used at own risk. I do not stand in for any problems or blown turbo's. My special thanks go out to Matt and Tomek who helped me with all this information and tuning advice. I hope you enjoy the information.